Anti-angiogenetic therapies for central nervous system metastases from non-small cell lung cancer
Central nervous system (CNS) metastases are common in patients with advanced non-small cell lung cancer (NSCLC), occurring in 24% to 44% of patients in the course of their disease and confer significant morbidity and mortality. Systemic therapies have been deemed ineffective in brain metastases (BM) under the hypothesis that the blood-brain barrier (BBB) limits their delivery to the brain. Angiogenesis, which is mainly mediated by vascular endothelial growth factor (VEGF) pathway, is crucial for tumor survival, growth and invasion both in primary and metastatic brain lesions. Two major categories of agents have been developed to target this pathway: antibody-based agents and VEGF receptor tyrosine kinase inhibitors (TKIs). Clinical benefits have been shown with anti-angiogenetic therapies in the treatment of metastatic NSCLC. However, patients with CNS metastases were often excluded from trials with these agents, due to concerns about a potentially greater risk of cerebral haemorrhage and thromboembolic disease. Therefore, the overall efficacy and safety of angiogenetic agents in patients with BM from NSCLC are yet to be clarified. This paper aims to review available data about the efficacy and safety of anti-angiogenetic therapies for CNS metastases in NSCLC patients.